Precipitation Warning and Canopy Practices

 

 Greetings Dear Growers,

Apologies for the late posting; I was away for a conference last week.

With rainfall totaling over 200 mm in some areas this past week, many of you had questions about spray products and frequency. Just a reminder that it is very unlikely that any effective fungicide residue remains on the vines after that significant rainfall; keeping on top of disease pressure is paramount.

As we should be receiving more rain this week, here are some guidelines and recommendations provided by Dr. Kevin Ker:

Please remember: It is highly encouraged to have re-applied fungicides in advance of upcoming rain events to maintain high levels of disease protection.

Water Use:

Be sure you are also using enough water to thoroughly cover all susceptible tissues. With rapidly expanding and near-full canopies now present, you should be using at least 500 L of water per ha or more to provide proper spray coverage. At vigorous locations with big canopies, 750 L of water per hectare is preferred.

 

Water is the primary carrier of pesticides from the spray tank to the plant tissues and should be continually adjusted to match the canopy development at your farm. If you are identifying disease infections in hidden/hard to reach areas of the canopy or on the backside of clusters, you are not achieving optimal spray coverage and should consider increasing your water output.

 

Disease pressure:  

Berries are highly susceptible to infections from Downy Mildew, Powdery Mildew and Black Rot until veraison is well underway. Green tissues such as leaves, petioles, shoots and rachis tissues are also highly susceptible to mildew and black rot infections, so it is important to recover following wash-off rain events, keep tight spray intervals of 7-9 days and continue using good locally systemic fungicides where possible.

Vineyard Practices:  

Carry on with your fruit zone leaf removal activities as this will open the fruit zone allowing for better air flow and spray penetration around berries. It is advised to remove basal /fruit zone leaves that are layered in stages on white cultivars, so they have time to adapt to the new conditions.

Risks Associated with excessive leaf removal:

If you are too aggressive in leaf removal around clusters, leaving the fruit fully exposed in white cultivars, you risk burning or baking the newly exposed berries. It is common to remove leaves on the east side of the row first then follow-up by removing leaves on the west side 7-10 days later. You can be more aggressive in your first leaf removal pass in red cultivars, removing leaves from both sides of the row.

As previously mentioned by Dr. Deb Moreau, sightings of Japanese Beetle and

Phylloxera are increasingly prevalent.

 

                               Japanese Beetle Leaf Damage               Phylloxera Damage

If you have previously used Movento for phylloxera control, please consult the Perennia online pest tool to evaluate other products if you need follow up sprays. Read and follow the label rates.

 

Below, please see the Precipitation, GDD and Phenological Observations, provided by the Kentville Research Station up to July 11^th, 2024.

 Table 1: GDD:                                                                                   

Growing degree days, base of 10 °C starting on April 1
Current Year	10-Year Average
462.5	379.0

 

 

 

 

Table 2: Precipitation:  

Month	25-Year Average (mm)	Current Year (mm)
April	81.5	54.0
May	74.0	29.8
June	95.5	83.0
July	81.3	99.8 **
August	94.5
September	104.1
October	115.8

Table 3. Phenological stages of three varieties . Bud break for all three varieties was between May 18 and May 20, 2024.

Date of Assessment	Marquette	L’Acadie blanc	New York Muscat
11-July	BERRIES PEA SIZE	BERRIES PEPPER CORN TO PEA SIZE	BERRIES PEPPER CORN TO PEA SIZE

 

Our observations: Date of Assessment: 11 July 2024.

•        Frontenac

Berries pea-size

•         Pinot Noir

Setting: Young berries growing; bunches are at right angles to the stem.

•         Chardonnay

Setting; some berries >2mm

Lastly, a gentle reminder about the Cover cropping info session next Wednesday at 5:30pm at Benjamin Bridge winery.

 

Thank you all for your time this week, and looking forward to seeing many of you at the info session next week.

Cheers!

Katarina Vucic

Viticulture Specialist
Perennia Food and Agriculture
Email kvucic@perennia.ca
Office 902-678-7722

Cell 902-599-1390

 

www.perennia.ca